عنوان مقاله [English]
According to definitions in economical literature, efficiency means maximum output with a definite amount of input or minimum input with a definite amount of output. In general, there are two main approches for measuring efficiency; Parametric method and Non-parametric method. In this paper, the performance efficiency of the Iranian Provincial Water and Wastewater Enterprises is evaluated using the Nonparametric method which is based on mathematical programming methods. The main advantage of data envelopment analysis in comparison with other methods is to evaluate the efficiency of units that have several input and output. In this paper, according to output and input data for the Iranian year of 1385, the efficiency of Enterprises in different provinces were evaluated considering the constant return to scale and the variable return to scale. The results showed that, subject to the constant return to scale, the nine provinces of Hamedan, Markazi, Southern Khorasan, Sistan and Balochestan, Mazandaran, Zanjan, Kohgiloyeh and Boyerahmad, Qazvin, and Tehran have the highest efficiencies with the average of 79 percent. For the second assumption, Kerman, Fras, Semnan, and Ilam are the efficient provinces with the average efficiency of 86 percent. Finally, the operation of Hamedan Water and Wastewater Enterprise is considered as a pattern that other inefficient enterprises should follow.